1. Technical Field of the Invention
The present invention relates to apparatus for an image on photosensitive material such as a recording unit of a color scanner, a laser printer and a laser plotter and, more particularly, relates to improvement in facilitation of manufacture and maintenance thereof.
2. Related Art
FIG. 1 illustrates a conventional apparatus of a color laser plotter. Held to a recording drum 102 is a photosensitive material 104, which is driven to rotate by a driving source (not shown). To a recording head 106, a recording signal is fed. Receiving the signal, the recording head 106 emits a laser beam corresponding to the recording signal toward the photosensitive material 104 on the recording drum 102, thereby making the photosensitive material 104 exposed to the laser beam. The recording head 106 is arranged to be movable in the direction A parallel to the axial direction of the recording drum 102. Rotation of the recording drum 102 and movement of the recording head 106 render the photosensitive material 104 to be entirely exposed to the laser beam.
However, the conventional apparatus as mentioned above has confronted some problems as described below. When the photosensitive material 104 is sensitive to natural light , it is necessary to accommodate both the recording drum 102 and the recording head 106 into an enclosure 108 to shield the photosensitive material 104 from the natural light. The enclosure 108 is so large in size as to make the assembling thereof laborious work, and moreover the filling of clearances difficult. In brief, the large-sized enclosure 108 is caused increase in cost heretofore.
Also, since a light source (not shown) produces heat in the recording head 106, the enclosure 108 is required to cool therein. It, however, is difficult to satisfy both the requirements of light shielding and cooing at the same time.
Further, in exercising maintenance of the recording drum 102 and the recording head 106, the large-sized enclosure 108 is necessarily removed, causing reduction in work efficiency.